<template>
  <div class="resize" title="调整宽度">⋮</div>
</template>
<script>
export default {
  name: 'DragAdjustWidth',
  components: {},
  props: {
    styleLoc: {
      type: Object,
      default: () => {}
    }
  },
  data() {
    return {
      screenWidth: document.body.clientWidth
    };
  },
  watch: {
    screenWidth(newVal, oldVal) {
      const styleLoc = this.styleLoc;
      var resize = document.getElementsByClassName('resize');
      var mid = document.getElementsByClassName(styleLoc.right);
      for (let i = 0; i < resize.length; i++) {
        mid[i].style.width = newVal - resize[i].offsetLeft + 'px';
      }
    }
  },
  created() {},
  mounted() {
    this.dragControllerDiv();
    window.addEventListener('resize', () => {
      this.screenWidth = document.body.clientWidth;
    });
  },
  beforeDestroy() {
    window.onresize = null;
  },
  methods: {
    dragControllerDiv() {
      const styleLoc = this.styleLoc;
      var resize = document.getElementsByClassName('resize');
      var left = document.getElementsByClassName(styleLoc.left);
      var mid = document.getElementsByClassName(styleLoc.right);
      var box = document.getElementsByClassName(styleLoc.box);
      const that = this;
      for (let i = 0; i < resize.length; i++) {
        // 鼠标按下事件
        resize[i].onmousedown = function(e) {
          // 颜色改变提醒
          resize[i].style.background = '#818181';
          var startX = e.clientX;
          resize[i].left = resize[i].offsetLeft;
          that.compatibleStyle(mid[0], 'none');
          // 鼠标拖动事件
          document.onmousemove = function(e) {
            var endX = e.clientX;
            var moveLen = resize[i].left + (endX - startX); // （endx-startx）=移动的距离。resize[i].left+移动的距离=左边区域最后的宽度
            var maxT = box[i].clientWidth - resize[i].offsetWidth; // 容器宽度 - 左边区域的宽度 = 右边区域的宽度
            if (moveLen < 200) moveLen = 200; // 左边区域的最小宽度为32px
            if (moveLen > maxT - 150) moveLen = maxT - 150; // 右边区域最小宽度为150px
            resize[i].style.left = moveLen; // 设置左侧区域的宽度

            for (let j = 0; j < left.length; j++) {
              left[j].style.width = moveLen + 'px';
              mid[j].style.width =
                                box[i].clientWidth - moveLen + 'px';
            }
          };
          // 鼠标松开事件
          document.onmouseup = function(evt) {
            that.compatibleStyle(mid[0], 'auto');
            // 颜色恢复
            resize[i].style.background = '#d6d6d6';
            document.onmousemove = null;
            document.onmouseup = null;
            resize[i].releaseCapture && resize[i].releaseCapture(); // 当你不在需要继续获得鼠标消息就要应该调用ReleaseCapture()释放掉
          };
          resize[i].setCapture && resize[i].setCapture(); // 该函数在属于当前线程的指定窗口里设置鼠标捕获
          return false;
        };
      }
    },
    compatibleStyle(node, info) {
      if (node.getElementsByTagName('iframe').length) {
        node.getElementsByTagName(
          'iframe'
        )[0].style.pointerEvents = info;
      }
      if (node.getElementsByTagName('embed').length) {
        node.getElementsByTagName(
          'embed'
        )[0].style.pointerEvents = info;
      }
    }
  }
};
</script>
<style lang="less" scoped >
/*拖拽区div样式*/
.resize {
    cursor: col-resize;
    // float: left;
    // position: relative;
    // top: 300px;
    background-color: #d6d6d6;
    border-radius: 5px;
    margin-top: -10px;
    width: 10px;
    height: 50px;
    line-height: 50px;
    background-size: cover;
    background-position: center;
    /*z-index: 99999;*/
    font-size: 32px;
    color: white;
    left: -5px;
    position: relative;
    z-index: 99;
    display: flex;
    justify-content: center;
}
/*拖拽区鼠标悬停样式*/
.resize:hover {
    color: #444444;
}
</style>

